const std = @import("std");
const api = @import("api.zig");
const gpu = @import("gpu.zig");
const cpu = @import("cpu.zig");

// 显示模式结构体
pub const DisplayMode = struct {
    width: u32,
    height: u32,
    refresh_rate: u32,
    pixel_format: u32,
    pitch: u32, // 每行字节数
};

// 显示设备ID
pub const DisplayDeviceId = u64;

// 显示设备结构体
const DisplayDevice = struct {
    id: DisplayDeviceId,
    name: []const u8,
    vendor_id: u32,
    device_id: u32,
    modes: std.ArrayList(DisplayMode),
    current_mode: ?DisplayMode,
    primary: bool,
    initialized: bool,
};

// 显示管理器
pub const DisplayManager = struct {
    allocator: std.mem.Allocator,
    devices: std.ArrayList(DisplayDevice),
    next_device_id: DisplayDeviceId = 1,
    initialized: bool = false,

    // 初始化显示管理器
    pub fn init(allocator: std.mem.Allocator) !DisplayManager {
        var manager = DisplayManager{
            .allocator = allocator,
            .devices = std.ArrayList(DisplayDevice).init(allocator),
        };

        // 在实际系统中，这里会枚举并初始化显示设备
        std.log.info("Display Manager initialized", .{});

        // 模拟添加一个显示设备
        try manager.addVirtualDisplay();

        manager.initialized = true;
        return manager;
    }

    // 添加虚拟显示设备（用于开发和测试）
    fn addVirtualDisplay(self: *DisplayManager) !void {
        var device = DisplayDevice{
            .id = self.next_device_id,
            .name = "Virtual Display",
            .vendor_id = 0x1234,
            .device_id = 0x5678,
            .modes = std.ArrayList(DisplayMode).init(self.allocator),
            .current_mode = null,
            .primary = true,
            .initialized = false,
        };

        // 添加一些标准显示模式
        try device.modes.append(DisplayMode{
            .width = 1920,
            .height = 1080,
            .refresh_rate = 60,
            .pixel_format = 0x01, // 假设RGB888格式
            .pitch = 1920 * 4, // 假设每行4字节（RGBA8888）
        });

        try device.modes.append(DisplayMode{
            .width = 1280,
            .height = 720,
            .refresh_rate = 60,
            .pixel_format = 0x01,
            .pitch = 1280 * 4,
        });

        try device.modes.append(DisplayMode{
            .width = 800,
            .height = 600,
            .refresh_rate = 60,
            .pixel_format = 0x01,
            .pitch = 800 * 4,
        });

        device.initialized = true;
        try self.devices.append(device);
        self.next_device_id += 1;

        std.log.info("Added virtual display device: id={}", .{device.id});
    }

    // 获取显示设备列表
    pub fn getDevices(self: *DisplayManager) []const DisplayDevice {
        return self.devices.items;
    }

    // 获取指定显示设备
    pub fn getDevice(self: *DisplayManager, device_id: DisplayDeviceId) ?*DisplayDevice {
        for (self.devices.items) |*device| {
            if (device.id == device_id and device.initialized) {
                return device;
            }
        }
        return null;
    }

    // 获取显示设备的模式列表
    pub fn getDeviceModes(self: *DisplayManager, device_id: DisplayDeviceId) ?[]const DisplayMode {
        const device = self.getDevice(device_id);
        if (device == null) {
            return null;
        }
        return device.?.modes.items;
    }

    // 设置显示模式
    pub fn setDisplayMode(self: *DisplayManager, device_id: DisplayDeviceId, mode_index: u32) bool {
        if (!self.initialized) {
            return false;
        }

        const device = self.getDevice(device_id);
        if (device == null) {
            std.log.err("Display device not found: id={}", .{device_id});
            return false;
        }

        if (mode_index >= device.?.modes.items.len) {
            std.log.err("Invalid mode index: {}", .{mode_index});
            return false;
        }

        device.?.current_mode = device.?.modes.items[mode_index];
        std.log.info("Set display mode: device_id={}, width={}, height={}, refresh_rate={}",
            .{device_id, device.?.current_mode.?.width, device.?.current_mode.?.height, device.?.current_mode.?.refresh_rate});

        // 在实际系统中，这里会执行相应的模式设置操作
        return true;
    }

    // 获取当前显示模式
    pub fn getCurrentMode(self: *DisplayManager, device_id: DisplayDeviceId) ?DisplayMode {
        const device = self.getDevice(device_id);
        if (device == null or device.?.current_mode == null) {
            return null;
        }
        return device.?.current_mode.?;
    }

    // 将缓冲区提交到显示设备
    pub fn presentBuffer(self: *DisplayManager, device_id: DisplayDeviceId, buffer_id: gpu.GpuResourceId) bool {
        if (!self.initialized) {
            return false;
        }

        const device = self.getDevice(device_id);
        if (device == null or device.?.current_mode == null) {
            std.log.err("Cannot present buffer: invalid device or mode", .{});
            return false;
        }

        // 检查缓冲区是否为有效的GPU资源
        const buffer = gpu.global_gpu_manager.getResourceInfo(buffer_id);
        if (buffer == null or buffer.?.type != .texture) {
            std.log.err("Invalid buffer resource: id={}", .{buffer_id});
            return false;
        }

        const mode = device.?.current_mode.?;
        const buffer_size = mode.width * mode.height * 4; // 假设RGBA8888格式

        if (buffer.?.size < buffer_size) {
            std.log.err("Buffer too small for display mode: size={}, required={}",
                .{buffer.?.size, buffer_size});
            return false;
        }

        std.log.info("Presenting buffer to display: device_id={}, buffer_id={}, buffer_address=0x{x}",
            .{device_id, buffer_id, buffer.?.address});

        // 在实际系统中，这里会执行页面翻转或帧缓冲区更新操作
        return true;
    }

    // 设置主显示设备
    pub fn setPrimaryDevice(self: *DisplayManager, device_id: DisplayDeviceId) bool {
        const device = self.getDevice(device_id);
        if (device == null) {
            return false;
        }

        // 首先清除所有设备的主标志
        for (self.devices.items) |*d| {
            d.primary = false;
        }

        // 设置指定设备为主设备
        device.?.primary = true;
        std.log.info("Set primary display device: id={}", .{device_id});
        return true;
    }

    // 获取主显示设备
    pub fn getPrimaryDevice(self: *DisplayManager) ?*DisplayDevice {
        for (self.devices.items) |*device| {
            if (device.primary and device.initialized) {
                return device;
            }
        }
        return null;
    }

    // 启用显示设备
    pub fn enableDevice(self: *DisplayManager, device_id: DisplayDeviceId) bool {
        const device = self.getDevice(device_id);
        if (device == null) {
            return false;
        }

        // 在实际系统中，这里会执行启用设备的操作
        std.log.info("Enabled display device: id={}", .{device_id});
        return true;
    }

    // 禁用显示设备
    pub fn disableDevice(self: *DisplayManager, device_id: DisplayDeviceId) bool {
        const device = self.getDevice(device_id);
        if (device == null) {
            return false;
        }

        // 在实际系统中，这里会执行禁用设备的操作
        std.log.info("Disabled display device: id={}", .{device_id});
        return true;
    }

    // 清理资源
    pub fn deinit(self: *DisplayManager) void {
        // 释放所有设备的模式列表
        for (self.devices.items) |*device| {
            device.modes.deinit();
        }

        self.devices.deinit();
        std.log.info("Display Manager deinitialized", .{});
    }
};

// 全局显示管理器实例
pub var global_display_manager: DisplayManager = undefined;